As you pack the car or board the train to pass the coming days with far-flung family, there may be a seasonal song in your heart. Alternatively, you may be gripped by gnawing dread – of stewed living rooms, blaring televisions and the exhumation of family hatchets buried years before. But save for those on whom fate has foisted solitude, quirky individuals who choose it, and those with truly dysfunctional familial relationships, this is a time of year which most of us are grateful not to have to pass alone.

The link between health and companionship has become clearer over the past two decades, and one celebrated study suggests that the increased risk of early death that comes with total isolation in any given year is equivalent to smoking three packets of cigarettes a day. The prospect of a yuletide reunion with a niggling sibling or an unspeakable uncle might render such sociable sentiments dubious, but the reality that people are pack animals was this week underlined by poignant analysis of the differing fortunes of musical soloists as against group performers. The researchers set out with an open mind to interrogate why there are so many premature pop deaths, with drugs and early exposure to fame among many potential explanations. But when the numbers were crunched, one statistic stood out: standalone artists were about twice as likely to die prematurely as those in a band. There are, perhaps, more Michael Jacksons, Amy Winehouses and Nick Drakes than there are Keith Moons because it is easier to withstand the pressures of fame through the camaraderie of a group.

If atomism is unhealthy, the drop in divorces recorded on Thursday would appear to be good news. There are still five times as many separations as there were in 1960, but there has now been a definite downward drift over the best part of a decade. So is the societal foundation stone of the family newly secure? Two caveats caution against that conclusion. First, one cannot divorce without first getting married, as steadily fewer have done since the 1970s; the declining divorce rate is partly an automated echo of this preceding trend. Secondly, we are witnessing the effects of a recession which – the charities say – is requiring unhappy families to sit things out in their own way in unhappy homes. Legal costs and housing shortages caused divorce to dip during America's Great Depression, and these bleak adhesives are now holding British couples together too.

A more instructive guide to Britain's social fabric than the divorce rate came in the census, published early this month. The headlines were made by the waxing of migration and the waning of Christianity, but shifts in how far people do and do not live together are arguably even more important. If we strip out the question of marriage, an institution whose social meaning has changed in a less Christian era, and ask only whether people are living alone or together, we can see solitude on the march. The growing band of cohabiting families since 2001 exactly offsets the dwindling number of married parents. More significantly, however, the decades-old upward creep in the tally of lone-parent families continues again, this time with a rise of more than 250,000. Among the childless, too, there is a disproportionate rise in single living. More fragmented families would be less of a worry if they were accompanied by tighter bonds of friendship among the wider community, but there are scant signs of that. Polling for the respected Hansard Society suggests that the last couple of years have witnessed a drop-off of about a quarter in volunteering.

It is, perhaps, too early to pronounce that the imagined "big society" has splintered into an archipelago of lonely islands. And yet the warning signs are there. Whatever the trials of scrambling through Christmas with family or old friends, don't forget to be grateful for them. And let's hope 2013 is a year where we can all remember that we are stronger together.